1. Field of the Invention
The present invention relates to controlling a point-of-load (“POL”) regulator output, or more particularly, to a system and method of utilizing output-timing data to control at least one output timing parameter of a POL regulator.
2. Description of Related Art
Point-of-load (“POL”) regulators, which are also referred to as voltage regulators or DC/DC converters, are commonly used in conjunction with electronic circuits. This is because the voltage/current requirements of electronic circuits typically differ from the voltage that is readily available or the current that can practically be delivered. For example, some electronic devices only include a single voltage input (e.g., 12v), but require different voltages for circuits contained within (e.g., 3v, 5v, 9v, etc.). A common solution is to design multiple POL regulators within the device for converting the single input voltage into multiple voltage levels.
Similarly, some electronic devices include circuits that require low voltage (e.g., 1v), high current (e.g., 100 A) power supplies. This is problematic in that it is impractical to deliver high current at low voltage levels over a relatively long distance and still meet desired regulation performances. A common solution is to use a high voltage, low current power supply and design a POL regulator near the internal circuit. This allows low current to travel throughout the device, and provides a low voltage, high current power supply (i.e., using the POL regulator) near the internal circuit.
Traditionally, POL regulators operate in conjunction with at least one power supply controller. The controller (1) activates and partially programs the POL regulator by providing data directly to the POL regulator, (2) monitors the output of the POL regulator by measuring data external to the POL regulator, and (3) allows the output of the POL regulator to be transmitted to an external load circuit by controlling an external switch. Specifically, the controller provides the POL regulator with output-voltage-set-point data and enable data. The POL regulator, in response to receiving the enable data, produces an output having a voltage level in accordance with the output-voltage-set-point data. The output of the POL regulator is then measured by the controller. If the output is correct, the controller activates an external transistor switch, which allows the output to be transmitted to the external load circuit. If a particular output slew rate is required, the controller can toggle or control linearly the external transistor switch to achieve the desired slew rate. Thus, the power supply controller controls the output timing parameters of each POL regulator (e.g., sequencing, slew rate, etc.) by controlling a plurality of external transistor switches.
The drawback with such a control system is that it adds complexity, expense and size to the control system by requiring the controller to communicate with multiple devices (e.g., a POL regulator and an external transistor switch) to control the output timing parameters of a single POL regulator. Thus, it would be advantageous to have a system and method of controlling the output timing parameters of a POL regulator that overcomes these drawbacks.